A screw tool having a freewheel gear is shown in DE 20 2009 000 005 U1. There, an output shank is inserted in an output opening. The output opening has a square cross-section. Locking means are provided which hold the output shank in different axial positions. The output shank can assume a left-hand screw position in which an end portion of the output shank protrudes farther out of the gear head than the opposing end portion of the output shank so that a socket can be attached onto the output portion that protrudes farther out of the gear head, which socket, due to the directional lock, can be rotated only in one direction. The output shank can be axially displaced in such a manner that the other end portion protrudes farther out of the output opening than the now opposing end portion so that then a socket can be attached onto the other end portion, which socket can be used for screwing in the opposite direction of rotation.
A ratchet having a locking means which can be brought in a release position by actuating a pushbutton is described in U.S. Pat. No. 3,208,318 and DE 10 2004 032 341 A1.
DE 10 2007 025 078 A1 describes a torque transmission device having a switch-over latching ball.
U.S. Pat. No. 4,631,989 describes a plurality of exemplary embodiments of a ratchet. In one exemplary embodiment, the output shank is displaceably disposed in the ratchet head for the purpose of switching between left- and right-hand positions. In another exemplary embodiment, the output shank is fixedly connected to the ratchet head. In the output shank there is a pin which protrudes beyond the head's wide side opposite to the output shank. By applying pressure on the pin, a locking ball can be displaced from a locking position into a release position.
U.S. Pat. No. 6,067,881 describes a screw tool having a freewheel gear in the case of which an output shank protrudes out of the gear head, in which output shank there is an actuation pin which protrudes beyond the head's wide side opposite to the output shank. Here too, by applying pressure on the pin, a locking position can be displaced into a release position.
In the case of the aforementioned screw tool, the gear head is formed as a hammer. If a socket is attached onto the output shank, this socket has to be coupled to the output shank in an axially fixed manner. In addition, it has to be ensured that when using the tool as a hammer, the output shank does not change in an uncontrolled manner between its two screw positions.